docs: add Open in Colab badge to README (simulator)

Author: yz-rrr

simulator/README.md

@@ -78,17 +78,26 @@ To run the simulators in a Google Colab environment:
 For `sim1.py`：
 
 ```
-sim = CollostructionalComparisonSimulatorNCWr()
-sim.display()
+simulator1 = CollostructionalComparisonSimulatorNCWr()
+simulator1.display()
 ```
 
 For `sim2.py`：
 
 ```
-sim = CollostructionalComparisonSimulatorKMbr()
-sim.display()
+simulator2 = CollostructionalComparisonSimulatorKMbr()
+simulator2.display()
 ```
 
+For `sim3.py`：
+
+```
+simulator3 = CollostructionalComparisonSimulatorNCWr()
+simulator3.display()
+```
+
+Demo: [![Open In Colab](https://colab.research.google.com/assets/colab-badge.svg)](https://colab.research.google.com/github/garage-phi/collostructional-analysis-python/blob/main/simulator/simulator_demo.ipynb)
+
 
 ## Theoretical Note: The PMI-LOR Behavior